Logic gates are used to perform various logic operations, most notably AND, OR, NAND, and NOR. Typically, a single logic gate is made of several components which together provide a logic operation. For example, an AND gate includes components which together provide an AND operation. Further, logic devices are desired to have various characteristics. For example, logic devices are generally desired to be concatenatable and nonlinear. A logic device is concatenatable if the output of the logic device may be provided to the input of another logic device. Nonlinearity corresponds to the response of the logic device having two states based on the input. A logic device may thus allow the digitization of analog information. Further, the logic device is desired to be free of feedback. Thus, the output of the logic device should not affect the inputs if the output is not intentionally fed back to the input. Gain in a logic device is desired to allow a sufficient output signal using the supply voltage of the circuitry. Finally, a set of logic devices built on a particular technology is desired to provide a full set of Boolean operations. For example, at least a NOT operation and an AND operation may desired. Other operations may be formed either from the basic components of the technology or from the NOT and AND gates. Finally, the logic devices are desired to be sufficiently fast, not consume an undue amount of energy and be manufacturable at desired densities.
FIG. 1 depicts a conventional magnetic switch 10, which may be considered a conventional magnetic logic gate. The conventional magnetic switch 10 includes contacts 12, 20, 22, and 30, free layer 14 and 24, barriers 16, 18, 26, and 28, isolation layers 17 and 27, and channel 30. Depending upon the value of the voltage Vsupply, the spins in the channel 40 may be in one of two states. The free layer 24 magnetization may then be in one of two states. These states can be determined on the output voltage, Vout. Thus, the structure 10 may function as a switch. However, the conventional magnetic switch 10 may not be easily used to generate other logic gates having the desired characteristics. For example, the current through the conventional magnetic switch 10, switching speed, ease of fabrication and other issues may prevent the conventional magnetic switch 10 from use in logic devices.
Accordingly, what is needed is a method and system that may allow for magnetic logic gates. The method and system described herein address such a need.